Knee support



FIG. 1 is a perspective view of a knee support showing our new design; and,

FIG. 2 is a top view thereof.

In the following figures, the dash-dash-dash broken lines illustrate portions of a knee support which forms no part of the claimed design. The dash-dot-dash lines illustrate the boundaries of the design that form no part of the claimed design. 

The ornamental design for a knee support, as shown and described. 